In the retail jewelry business it is desirable to be able to securely and effectively set a variety of combinations of stones and settings. For example, customers may want special combinations of birthstones in selected ring settings thus, it is most advantageous to the dealer to be able to set these stones when requested by the customer and while he waits.
The present invention relates to a manually operable tool for the setting of stones in stone settings, and more particularly it comprises a frame in which a vertically oriented die tipped shaft can be axially displaced by a cam mechanism which, being turned by a handle, provides a maximum mechanical advantage when the shaft is in its most downward position. A stone setting supporting cylindrical arbor is so located and interconnected with the frame that when the specially shaped die tip of the shaft is in its lowest position it engages and crimps the prongs of the setting around the stone.
A tool constructed according to this invention is especially convenient for setting stones in rings, the settings for which fit simply over the arbor. Other devices, not having this feature have much more complicated clamping or other means for retaining settings. Further, a tool constructed according to this invention provides a maximum mechanical advantage and, therefore, a maximum of force applied to bend the prongs of setting just as the tip reaches its maximum downward displacement. This feature makes a tool constructed according to this invention very stable in operation since the operator has to apply very little force to secure the stone to the setting and is therefore highly unlikely to upset the tool, while in operation. Other stone setting tools requiring larger external forces for their operation are unstable unless securely clamped, whereas an embodiment of the present invention, never requiring more than slight external pressure, need not be fastened down, and as a result, is more portable.
Another consequence of the cam operated shaft is that no force can be applied to it to move the tip past a pre-set downward most engaging position so that neither stones nor settings can be destroyed by careless operation. Known stone setting devices have used complicated spring loaded stone setting supports to reduce the likelihood of damage. The present device however, eliminates this problem.
One object of this invention is to provide an easily operated stone setting press of inexpensive design.
Another object of this invention is to provide a highly portable stone setting press which, because little force need be externally applied to it, does not have to be clamped down, or have a heavy base, for stable operation.
Still another object of this invention is to provide a stone setting press in which the prong bending means cannot be forced past a limiting point and which therefore cannot shatter the stone being set.
A further object of this invention is to provide a stone setting press which is especially adapted to handle ring settings and requires no clamping means for such settings.
Still another object of this invention is to provide a stone setting press which completely and accurately crimps the prongs of a setting by providing the application to the prongs of maximum force as they approach their optimal positions around the stone.
These and other objects and features of this invention may be better understood by consideration of the following description of one embodiment thereof.